The IAEA inspectors just in Iran were there to inspect the solid-fuel rocket facility at Parchin. They were quickly refused access.
Iran is going full speed to develop solid-fuel as that is the key to range-payload of their rockets.
The inspectors could have also noticed any, say, N Korean smiling faces at Parchin also.
Actially, Iranian missile engineers has surpassed their North Korean counterparts.But looking North Korean satellite launch attempts, they used a satellite launcher that looks nothing like what we see in Iran. It was completely different, much bigger and heavier, and with three stages.